Citation: Oprsal, I., and J. Zahradnik, Three-dimensional
finite difference method and hybrid modeling of earthquake ground motion,
J. Geophys. Res., 107(B8), 10.1029/2000JB000082, 2002, 16pp.
Received 28 November 2000; revised 28 September 2001; accepted 2 October
2001; published 16 August 2002.
(c) 2002 by the American Geophysical Union.
Finite Difference Method and Hybrid Modeling of Earthquake Ground
Ivo Oprsal (1), Jiri Zahradnik (2),
Swiss Seismological Service,
ETH-Hoenggerberg/HPP, CH-8093 Zuerich, Switzerland.
(On leave from (2))
Department of Geophysics,
Faculty of Mathematics and Physics, Charles University, V Holesovickách
2, 180 00 Praha 8, Czech Republic
A new two-step hybrid technique (hybrid) has been developed to estimate
the earthquake ground motion in 3D local models excited by external sources.The
main use of the technique the to fast evaluation of site effects and seismic
hazard, because our technique needs less computer memory and time than
all-in-one source-path-site computational methods.The ﬁrst step of the hybrid
requires an arbitrary 3D method (e.g.ﬁnite-difference (FD), discrete wavenumber,
ray, or analytical solution) to compute 3-component excitation on a grid
box surrounding a site of interest. A particular excitation contains information
on the source and path effects and is saved on disk as a time history.Depending
on the method used, the 1 st step may also contain non-planar topography.The
second step (3D FD) employs local structure and topography inside the excitation
box and a procedure that exactly couples the 1 st step results with the
2nd step. The speedup of the hybrid method is made possible through the
computation of the excitation (saved on disc) in the 1st step, and the
numerous uses of the FD on irregular grids in the 2 nd step of the hybrid.
The 2nd step computational model can be just a small spatial fraction of
the original source-path-site model. A practical parameter study example
of a point double-couple source and regional topography model (applied in
the 1 st step) with a local low-velocity basin structure and ridge (both
applied in the 2 nd step only) is presented.
KEYWORDS: earthquake ground motion, seismic waves, hybrid
modeling 3-D finite differences, site effects, parameter studies
Here you can retreive:
the manuscript (PDF, 0.7MB, 16 pp.)
the manuscript (PDF, 0.7MB, 16 pp.): http://www.agu.org/journals/jb/jb0208/2000JB000082/2000JB000082.pdf
the manuscript HTML: http://www.agu.org/journals/jb/jb0208/2000JB000082/index.html
(The 3D FD HYBRID code available
free on demand)
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